With the popularity and convenience of networking computer systems, data sharing among users through databases has become common in many business environments. Providing central access to information via databases requires careful consideration of database maintenance and management. Further, recovery techniques are essential in ensuring database coherence following a hardware/device failure or application logic failure.
In general, recovery techniques reset a system or data stored in a system to an operable state following damage and provide a process of rebuilding databases by restoring a backup copy.
In any data recovery system there are two points of interest:                First, the Recovery Point Objective (RPO), which defines the maximum planned variance between the original data and the backup copy.        Second, the Recovery Time Objective (RTO), which defines the maximum time for the re-establishment of service.        
One of the most simplistic forms of system backup includes physically transporting copies of data made on magnetic tapes to a remote archiving site. Generally, this requires a user to halt all database activity while making the backup tape. The disaster recovery process then involves using the backup tape to recover the databases.
A more modern form of system backup uses a network interconnection to perform periodic backups of a production site. The times when such backups occur is controlled by a network administrator. The method for restoring the application server includes installing a new system starting with hardware that has similar characteristics to the old system and restoring the backed up image of the system from the recovery site.
Another prior art system supplied by Veritas (available on the Internet for download via the URL: http://www.veritas.com/Products/www?c=product&refId=140 at the filing date of the present patent application) contemplates an architecture of software modules for controlling the various phases necessary for the correct execution of the backup procedure and the subsequent phase of restoring clients. In particular, the Veritas solution uses different servers for each separate functional aspect including a server for the control and management of backup operations, a server for the control of the client restore phase, a server that provides the clients with the programs and configurations necessary for the restore, and, finally, a server for the management of remote booting.
Another prior art solution is a Cisco Network Boot System described in a paper entitled “Cisco Network Boot Installation and Configuration Guide, Release 3.1”, available on the Internet for download via the URL: http://www.cisco.com/en/US/products/hw/ps4159/ps2160/products_installation_and_configuration_guide_book09186a00801a45b0.html (at the filing date of the present patent application) that makes copies of the entire system image including the operating system, the applications on the server and the data. The backup is performed manually by a network administrator. The Cisco solution provides the possibility of remotely executing a boot procedure over a network, provided that it has hardware characteristics identical to the primary server from which the replication was made. The recovery server is therefore able to restore a remote copy of the system image from across the network and re-offer the services previously assured by the primary server.
In US Patent publication US2004/0153698 A1, there is provided a system and method of disaster preparedness and restoration of service of damaged or destroyed telecommunication network elements. A computer-implemented method of disaster backup for network elements includes establishing connectivity to a plurality of network elements. A host computer may transmit one or more commands to the network elements for invoking a computer routine to create a plurality of computer readable service continuity data to a local memory of the network elements. An automated system of computer executable components for disaster recovery of network elements includes a computer executable controller component that is configured to select a plurality of network elements designated for disaster backup action. A computer executable engine component is configured to establish connectivity to the plurality of network elements and to transmit one or more commands to the network elements so as to replicate service continuity data for each of said network elements.
In US Patent publication US 2004/0078397 A1 a file system disaster recovery techniques provides automated monitoring, failure detection and multi-step failover from a primary designated target to one of a designated group of secondary designated targets. Secondary designated targets may be prioritized so that failover occurs in a prescribed sequence. Replication of information between the primary designated target and the secondary designated targets allows failover in a manner that maximizes continuity of operation. In addition, user-specified actions may be initiated on failure detection and/or on failover operations and/or on failback operations.